I will assume you are a Filipino with foreign blood. We have rules in changing the surname and they need to be followed strictly. Please follow the procedures below and it will be helpful if you have a lawyer assisting you.
This is a special proceeding that can be filed in a court.
CANCELLATION OR CORRECTION OF ENTRIES IN THE CIVIL REGISTRY
Sec. 1. Who may file petition. - Any person interested in any act, event, order or decree concerning the civil status of persons which has been recorded in the civil register, may file a verified petition for the cancellation or correction of any entry relating thereto, with the Court of First Instance of the province where the corresponding civil registry is located.
Sec. 2. Entries subject to cancellation or correction. - Upon good and valid grounds, the following entries in the civil register may be cancelled or corrected: (a) births; (b) marriages; (c) deaths; (d) legal separations; (e) judgments of annulments of marriage; (f) judgments declaring marriages void from the beginning; (g) legitimations; (h) adoptions; (i) acknowledgments of natural children; (j) naturalization (k) election, loss or recovery of citizenship (l) civil interdiction; (m) judicial determination of filiation; (n) voluntary emancipation of a minor; and (o) changes of name.
Sec. 3. Parties. - When cancellation or correction of an entry in the civil register is sought, the civil registrar and all persons who have or claim any interest which would be affected thereby shall be made parties to the proceeding. chanrobles virtua law library
Sec. 4. Notice and publication. - Upon the filing of the petition, the court shall, by an order, fix the time and place for the hearing of the same, and cause reasonable notice thereof to be given to the persons named in the petition. The court shall also cause the order to be published once a week for three (3) consecutive weeks in a newspaper of general circulation in the province.
Sec. 5. Opposition. - The civil registrar and any person having or claiming any interest under the entry whose cancellation or correction is sought may, within fifteen (15) days from notice of the petition, or from the last date of publication of such notice, file his opposition thereto.
Sec. 6. Expediting proceedings. - The court in which the proceeding is brought may make orders expediting the proceedings, and may also grant preliminary injunction for the preservation of the rights of the parties pending such proceedings.
Sec. 7. Order. - After hearing, the court may either dismiss the petition or issue an order granting the cancellation or correction prayed for. In either case, a certified copy of the judgment shall be served upon the civil registrar concerned who shall annotate the same in his record.